That would be Rakuv רקוב, just Raku doesn't have any meaning in Hebrew. It does sound similar when pronounced though.
(Hebrew word formation is from 3-consonant roots, not concatenation, so removing a letter doesn't give a related word. It's either an invalid word or a different root with 3rd voiceless consonant רקוא which is a not a root / רקוע Raku'a "flattened" but that doesn't sounds quite differently.)
